final Date date = format.parse(str, pos);
        if (date == null) {
            return null;
        }
        final int index = pos.getIndex();
        if (index == 0) {
            return null;
        }
        if (index < str.length()) {
            return null;
        }
        return date;
    }

    /**
     * Converts a {@link Date} to a {@link Calendar}.

				}
				// index is negative means is pointer
				if field.FieldType.Kind() == reflect.Struct {
					ef.StructField.Index = append([]int{fieldStruct.Index[0]}, ef.StructField.Index...)
				} else {
					ef.StructField.Index = append([]int{-fieldStruct.Index[0] - 1}, ef.StructField.Index...)
				}

    //                                                                              Index
    //                                                                      ==============
    /**
     * Show the index page.
     * @return The HTML response.
     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse index() {
        searchEngineApiManager.saveToken();

        final String index = fessConfig.getIndexDocumentUpdateIndex();
        return deleteBySessionId(searchEngineClient, index, sessionId);
    }

    /**
     * Deletes all documents associated with the specified session ID from the given index.
     *
     * @param searchEngineClient the search engine client to use for deletion
     * @param index the index name to delete documents from

import org.opensearch.index.query.RangeQueryBuilder;
import org.opensearch.index.query.RegexpQueryBuilder;
import org.opensearch.index.query.SpanTermQueryBuilder;
import org.opensearch.index.query.TermQueryBuilder;
import org.opensearch.index.query.TermsQueryBuilder;
import org.opensearch.index.query.WildcardQueryBuilder;
import org.opensearch.index.query.functionscore.FunctionScoreQueryBuilder;

    checkArgument(values.length > 0);
    double mean = values[0];
    for (int index = 1; index < values.length; index++) {
      double value = values[index];
      if (isFinite(value) && isFinite(mean)) {
        // Art of Computer Programming vol. 2, Knuth, 4.2.2, (15)
        mean += (value - mean) / (index + 1);
      } else {
        mean = calculateNewMeanNonFinite(mean, value);
      }
    }

{"index":{"_index":"fess_user.role","_id":"YWRtaW4="}}
{"name":"admin"}
{"index":{"_index":"fess_user.role","_id":"Z3Vlc3Q="}}

  @Override
  protected final int nextEscapeIndex(CharSequence csq, int index, int end) {
    while (index < end) {
      char c = csq.charAt(index);
      if ((c < replacementsLength && replacements[c] != null)
          || c > safeMaxChar
          || c < safeMinChar) {
        break;
      }
      index++;
    }
    return index;
  }

  /**

{"index":{"_index":"fess_user.user","_id":"YWRtaW4="}}

                    byte[] includeContent = "192.168.1.200 INCLUDEHOST\n".getBytes();
                    int[] index = { 0 };
                    when(mock.read()).thenAnswer(inv -> {
                        if (index[0] < includeContent.length) {
                            return (int) includeContent[index[0]++] & 0xFF;
                        }
                        return -1;
                    });